Imatinib, a tyrosine kinase receptor inhibitor (PDGFR α and β, DDR, c-KIT, CSF1R, ABL) approved for the treatment of chronic myeloid leukemia, had proven to reverse PAH in animal models and suggested to be clinically and hemodynamically effective as adjunctive treatment of patients with PAH in case reports and a phase-2 trial [98,99,100]. The gene discussed is CSF1R; the disease is pulmonary arterial hypertension.